Hydrostatic drives were originally controlled mechanically or hydraulically. In this case, a control element is typically assigned to each manipulated variable. Many of the electronically controlled systems used today have incorporated this control concept and usually map the control subtasks onto manipulated variables directly in a unique assignment.
A control, for example, is known from DE 10 2010 020 004 A1, in which torque control on a pump shaft is implemented in the sense of a power or torque controller. For this purpose, a piston displacement of the pump is set via an adjusting device.
In addition, a working pressure can be limited in a hydraulically controlled manner in order to thereby directly limit a tractive force, for example. Such methods can be used, for example, with rodless aircraft tractors.
A moment structure has become established in the automotive field, which coordinates a driver input at different levels with interventions of driving safety systems, assistance systems, transmissions, etc. Moment-based control methods for hydrostatic drives can be used for this purpose. As a precondition therefor, however, the drive system must contain a memory. This is used, for example, in a hydraulic power train (HPT) or with hydraulic regenerative braking (HRB).
Such a hydraulic power train is described, for example, in DE 10 2012 222 717 A1, and such hydraulic regenerative braking is described, for example, in DE 10 2010 020 004 A1.
Due to the direct action by the control elements on the manipulated variables in the methods mentioned, data input into the control system is therefore possible only within the context of the entire machine.
Therefore, it is desirable to enable a separation from a higher-order machine and drive or drive train and thereby permit data input into the drive without the machine.